• Home
• Julia

searchsortedlast

searchsortedlast(a, x, [by=,] [lt=,] [rev=false])

Returns the index of the last value in a less than or equal to x, according to the specified order. Returns 0 if x is less than all values in a.

Examples

In the Julia programming language, the function searchsortedlast(a, x, [by=<transform>,] [lt=<comparison>,] [rev=false]) is used to find the index of the last value in a that is less than or equal to x, based on the specified order. If x is less than all values in a, it returns 0. Here are some examples of how to use this function:

1. Find the last value less than or equal to a given number:

   julia> arr = [1, 3, 5, 7, 9];
   julia> searchsortedlast(arr, 6)
   3

   In this example, the function returns the index 3 since it is the last index where the value is less than or equal to 6.

2. Use a custom comparison function:

   julia> arr = ["apple", "banana", "grape", "orange"];
   julia> searchsortedlast(arr, "pear", lt = (a, b) -> length(a) < length(b))
   2

   Here, the function uses a custom comparison function to determine the order based on the length of the strings. It returns the index 2 since it is the last index where the length of the value is less than the length of "pear".

3. Perform a reverse search:

   julia> arr = [5, 4, 3, 2, 1];
   julia> searchsortedlast(arr, 3, rev = true)
   3

   In this example, the function performs a reverse search and returns the index 3 since it is the last index where the value is less than or equal to 3 in the reversed array.

Common mistake example:

julia> arr = [1, 3, 5, 7, 9];
julia> searchsortedlast(arr, 10)
0

In this example, the value 10 is greater than all the values in the array arr. Therefore, the function returns 0 as specified in the function's behavior when x is less than all values in a.

See Also

User Contributed Notes

Add a Note

The format of note supported is markdown, use triple backtick to start and end a code block.